FREQUENCY CHANGER CONTROL METHOD Russian patent published in 1996 - IPC

FIELD: converter engineering; transistorized power supplies for inductive heating. SUBSTANCE: frequency changer that has rectifier, capacitive filter, and bridge-type push-pull transistorized inverter, each of whose transistors is shorted out by switching capacitor and opposing diode and operating into inductive load, is controlled by supplying enabling and discabling pulses to transistorized inverter in turn from opposing diode that shapes them. Pulse length is set between 0.15 and 0.3 of output voltge period. Voltage across switching capacitors is checked. Next pair of transistors is driven in conduction as soon as voltage across switching capacitor become equal to a level 0 to 0.2 of maximum voltage level. EFFECT: improved operating reliability of frequency changer. 2 dwg